<div id="waveform"></div>
<br />
<div class="playButtons">
    <button nz-button [nzSize]="size" (click)="prev()" nzType="primary">Pre</button>
    <button nz-button [nzSize]="size" (click)="play()" nzType="primary">Play</button>
    <button nz-button [nzSize]="size" (click)="next()" nzType="primary">Next</button>
</div>